This application claims the benefit of Korean Application No. 99-39910, filed Sep. 16, 1999, in the Korean Industrial Property Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a method of recording/reproducing multi-channel data, and more particularly, to a method of recording/reproducing multi-channel data simultaneously in real time on a recording medium which requires high-speed recording.
2. Description of the Related Art
A conventional recording/reproducing apparatus in which real-time audio and/or video data is recorded and reproduced on a disc medium is shown in FIG. 1. A hard disc drive (HDD) 10 has a disc 11 for recording, a recording/reproducing head 12, a head arm 13 for moving the recording/reproducing head 12, a track buffer 14 for storing data to be read or recorded, and a spindle motor 15 for revolving the disc 11.
Channel A data is signal processed for recording, stored in an encoder buffer 20, and then sent to the track buffer 14 of the HDD 10. Channel B data recorded on the disc 11 is stored in the track buffer 14 after being read from the disc 11. The data stored in the track buffer 14 is sent to a decoder buffer 30 and is reproduced.
Two-channel recording/reproducing is performed in the HDD 10 of FIG. 1 as shown in FIG. 2. Channel A is a channel in which audio/video (A/V) data is to be recorded on a regularly continuous free space, and channel B is a channel in which data recorded on a regularly continuous space is to be reproduced.
The sequential procedures are repeatedly performed to accomplish simultaneous two-channel recording/reproducing as follows:
Step 1: for channel A, read data to be recorded from the track buffer 14 and record the data in a continuous free space.
Step 2: for channel B, read channel B data to write the channel B data to the track buffer 14 by moving the recording/reproducing head 12.
Step 3: again for the channel A, read data to be recorded from the track buffer 14 and record the data in a continuous free space.
Step 4: again for the channel B, read channel B data to write the channel B data to the track buffer 14 by moving the recording/reproducing head 12.
In order to record/reproduce data in real time, the A/V data must be processed so that the encoder buffer 20 of the recording/reproducing channel A does not overflow and the decoder buffer 30 of the recording/reproducing channel B does not underflow.
In the conventional art, the size of a buffer and the size of a continuous space that guarantee the bit rate of the A/V data of a single channel (one channel) are predetermined. However, since the size of the buffer and the continuous space are not predetermined when recording/reproducing two or more channels (i.e., multi-channels) the overflow of an encoder buffer 20 or the underflow of a decode buffer 30 may occur.
In addition, the frequent recording and deleting of the A/V data results in fragmentation of a free block, so that the A/V data cannot be recorded because there is a shortage of a continuous space which prevents an encoder buffer 20 overflow or a decoder buffer 30 underflow even if there is sufficient space for recording. Also, when recording/reproducing of two or more channels (i.e., when multi-channel recording/reproducing is performed) the size of the buffer and the continuous space must be considered in order to efficiently record/reproduce multi-channel data. Lastly, the characteristic of a recording medium due to a difference in the writing/reading speed between inner and outer circumferences must be considered for a recording medium such as a hard disc in which recording is performed at high speed in a uniform density by a constant angular velocity (CAV) technique.
To solve the above problems, it is a first objective of the present invention to provide a method of simultaneously recording/reproducing a plurality of audio/video (A/V) data streams on a recording medium, which requires high speed recording, in real time without a buffer overflow or underflow.
It is a second objective to provide an apparatus for simultaneously recording/reproducing a plurality of A/V data streams on a recording medium, which requires high speed recording, in real time without a buffer overflow or underflow.
Additional objects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Accordingly, to achieve the above objectives, the present invention provides a method of simultaneously recording/reproducing multi-channel data on a recording medium, the method comprising allocating the size of a continuous space on the recording medium, the size of channel buffers for recording, and the size of channel buffers for reproducing, based on the recording/reproducing speed information of a channel in which recording/reproducing is required according to a request for recording/reproducing, and, if there is a buffer filled with data to be recorded among the allocated channel buffers for recording, reading data from the buffer to record the data on the allocated continuous space, and if there is an empty buffer among the allocated channel buffers for reproducing, writing data read from the recording medium to the empty buffer.
The present invention also provides a disc recording/reproducing apparatus for recording/reproducing multi-channel data simultaneously on a recording medium, the apparatus including a plurality of channel buffers for recording/reproducing corresponding to multi-channels, and a recording/reproducing controller for, if there is a buffer filled with data to be recorded among the allocated channel buffers for recording, reading data from the buffer to record the data on the allocated continuous space, and if there is an empty buffer among the allocated channel buffers for reproducing, writing data read from the recording medium to the empty buffer. In the apparatus, the size of the continuous space on the recording medium, the size of the channel buffers for recording, and the size of the channel buffers for reproducing are allocated based on recording/reproducing speed information of a channel in which recording/reproducing is required according to a recording/reproducing request.